Exterior trim is the frame around your homes face. It outlines windows, caps corners, and draws the eye along rooflines. When it looks sharp, the whole house looks cared for. When it swells, cracks, or peels, it can make even a fresh paint job look tired. Trim sits right where weather works hardest. Sun bakes it. Rain soaks it. Wind drives grit into it. If you pick the wrong wood, you will be repainting sooner than you want, and you may be replacing boards long before they should be old.
The best wood for exterior trim depends on three things: your climate, your maintenance habits, and the look you want. Some woods behave like a good raincoat. Others act like a sponge with a nice grain pattern. This guide breaks down the top choices, what they do well, where they struggle, and how to make them last.
What exterior trim wood must handle
Trim fails in predictable ways. The end grain drinks water. Joints open as boards move. Paint lets go when moisture tries to escape. Insects find soft spots. The best trim woods resist rot, stay stable, and hold paint or stain without drama.
Before you choose, think about the stress points. Window and door casings see constant wetting and drying. Corner boards catch wind-driven rain. Fascia boards sit near roof edges where water can back up. If you have sprinklers, lower trim gets a daily shower. If you live near the ocean, salt and sun add another layer of punishment.
Also consider how the trim is built. Wide flat boards move more than narrow profiles. Built-up trim has more joints, which means more places for water to sneak in. A wood that stays straight and stable makes the whole system easier to seal and paint.
Clear vertical grain western red cedar
For many homes, clear vertical grain western red cedar is the sweet spot. It has natural oils that resist rot and insects. Vertical grain means the growth rings run more upright, which makes boards more stable and less likely to cup. It is light, easy to cut, and forgiving to install.
Cedar works well for painted trim and stained trim, but it needs the right prep. If you paint it, prime all sides, especially end grain. If you stain it, use a high-quality exterior stain and keep up with maintenance. Cedar can dent more easily than harder woods, so it is not ideal where ladders and lawn equipment bang into it.
Where cedar shines is in wet climates and on detailed trim. It takes crisp profiles, and it does not fight you as it dries. It is not the cheapest option, but it often costs less than the truly premium species.
Redwood (heartwood, not sapwood)
Redwood has a long history on exterior work for a reason. Heartwood redwood resists decay and handles moisture well. It machines cleanly and can look beautiful with a clear finish. For trim, it offers a nice balance of stability and durability.
The catch is quality. Redwood sapwood is far less rot resistant than heartwood. If you buy redwood for trim, you want boards that are mostly heartwood. In some regions, high-grade redwood can be expensive and harder to find. It can also be more variable in density, which affects dent resistance and how it holds fasteners.
Painted redwood can perform very well, but tannins can bleed if you skip the right primer. Use a stain-blocking exterior primer and do not rush the dry time.
Spanish cedar
Spanish cedar is not a true cedar, but it behaves like a premium exterior wood. It has strong natural resistance to rot and insects, and it stays relatively stable. It is often used for doors, shutters, and high-end millwork because it machines smoothly and smells pleasant when cut.
For exterior trim, Spanish cedar is a strong choice when you want crisp details and long life. It can be painted or finished clear. Like other oily woods, it benefits from careful surface prep and a compatible primer. It is usually priced in the premium range, but it can outlast cheaper woods by a wide margin.
Mahogany (genuine, not mystery mahogany)
Genuine mahogany is a classic for exterior doors and trim. It is stable, rot resistant, and strong. It holds sharp edges and stays flatter than many softwoods. If you want stained trim with a rich look, mahogany can feel like a tailored jacket on a house.
There are many products sold under the name mahogany. Some are durable, some are not. If you choose mahogany, buy from a reputable seller and confirm the species. For painted trim, mahogany can work, but many people choose it for clear or stained finishes because the grain is part of the appeal.
Mahogany needs UV protection if left with a clear finish. Sunlight can fade it and break down topcoats. A marine-grade exterior varnish system can look stunning, but it demands upkeep.
Accoya (acetylated wood)
If you want wood that behaves almost like a different material, Accoya is worth serious attention. It starts as fast-growing wood, then goes through an acetylation process that changes how it interacts with water. The result is exceptional dimensional stability and strong rot resistance. It is one of the best options for exterior trim where paint failure is the main enemy.
Accoya holds paint for a long time because it does not swell and shrink as much. Joints stay tighter. Caulk lines last longer. Miters do not open as quickly. It also works well in damp climates and near water.
It costs more than common woods, but it can pay you back with fewer repaints and fewer repairs. If you want the look of wood with a calmer maintenance schedule, Accoya is one of the top contenders.
Thermally modified wood
Thermally modified wood is heated in a controlled environment to improve stability and decay resistance. Different brands and species vary, but the general idea is the same: reduce the woods tendency to absorb moisture and make it less friendly to fungi.
For trim, thermally modified wood can be a good choice if you like a darker, modern look. It can be more brittle than untreated wood, so it needs careful handling and proper fastening. Paint performance depends on the specific product and surface texture. Many people use it with stains or penetrating finishes rather than thick paint films.
If you consider this route, ask for real exterior trim examples in your climate. Some products excel, and some are better suited to siding or rainscreen details than to tight-jointed trim.
Pressure-treated pine (only in specific situations)
Pressure-treated pine is common and affordable. It resists rot because preservatives are forced into the wood. That sounds perfect, but trim is not just about rot. It is also about movement and paint. Treated pine often has high moisture content when purchased. As it dries, it can twist, cup, and shrink. That movement can crack paint and open joints.
There are times when treated pine makes sense, such as trim close to grade or in areas that see constant wetting. Even then, it needs time to dry before painting, and it benefits from careful sealing of end grain. If you want crisp, stable trim that stays pretty, treated pine is rarely the best choice for visible areas.
Why not use interior-grade woods outside?
Poplar, MDF, and many finger-jointed interior trims fail quickly outdoors. Poplar can rot fast when water gets behind paint. MDF swells like a loaf of bread left in the rain. Finger-jointed pine can work outdoors only when it is specifically rated for exterior use and properly primed on all sides. Even then, it is a maintenance-forward choice.
Exterior trim is not the place to gamble. A small savings on boards can turn into a big bill once you factor in labor, paint, and the headache of replacing trim around windows.
Paint-grade vs stain-grade: choose the wood that suits the finish
If you plan to paint, stability and paint adhesion matter more than dramatic grain. Cedar, Accoya, and high-quality finger-jointed exterior trim stock can all work, but the best long-term paint performance often comes from woods that move less. Accoya is a standout here. Clear vertical grain cedar is also excellent when primed correctly.
If you plan to stain or use a clear finish, choose a wood that looks good and resists decay without relying on a thick paint film. Redwood heartwood, mahogany, and Spanish cedar are strong options. Keep in mind that clear finishes outside are not set it and forget it. They are more like a nice leather boot. They look great, but they need care.
Climate matters more than most people admit
In hot, dry climates, UV exposure and heat cycling can be brutal. Wood dries hard, then takes on moisture during rare storms. Paint can crack from the stress. Stable woods help, and so does good detailing that keeps water out.
In wet climates, rot resistance and end-grain sealing are the big issues. Cedar, redwood heartwood, Accoya, and Spanish cedar perform well. In cold climates, freeze-thaw cycles punish any spot where water can sit. Tight joints, sloped surfaces, and careful flashing matter as much as the species.
Near the coast, salt and sun speed up finish breakdown. Choose durable woods and plan on more frequent maintenance. Stainless fasteners become more necessary too.
Details that make any exterior trim last longer
Even the best wood can fail if water is allowed to linger. Trim should shed water the way a roof does. Flat horizontal surfaces need a slight slope. End grain should be sealed. Joints should be designed so water does not get trapped.
Back-priming is one of the simplest upgrades. Prime all sides before installation, especially end grain. It reduces moisture swings and helps paint stay put. Use a high-quality exterior primer suited to the wood. For tannin-rich woods like redwood and some cedars, use a stain-blocking primer to prevent discoloration.
Fasteners matter. Galvanized or stainless nails and screws reduce staining and corrosion. Pre-drilling helps prevent splits on harder woods. Caulk should be used where it makes sense, but it should not be asked to do the job of flashing. Caulk is a gasket, not a roof.
Finally, keep trim away from constant wetting. Adjust sprinklers. Maintain gutters. Make sure downspouts do not dump water onto corner boards. A good wood choice cannot overcome a bad water plan.
So what is the best wood for exterior trim?
If you want the most reliable painted trim with long service life and fewer headaches, Accoya is hard to beat. It stays stable, holds paint well, and resists decay.
If you want a traditional wood with strong performance and easier sourcing, clear vertical grain western red cedar is a top pick. It is a workhorse that looks good and lasts when detailed properly.
If you want stain-grade beauty and classic character, heartwood redwood and genuine mahogany are excellent, with Spanish cedar close behind. They cost more, but they can make a house look finished in a way that cheaper woods cannot imitate.
If budget is tight, you can still get decent results with exterior-rated finger-jointed trim or carefully handled treated pine, but expect more maintenance and be strict about priming and sealing.
High-end picks
Festool Kapex KS 120 REB Sliding Compound Miter Saw Clean, repeatable cuts for wide trim and detailed angles; a premium tool that helps expensive wood look its best.
Festool CT 36 E HEPA Dust Extractor Keeps the cut line visible and the jobsite cleaner; better dust control also helps primers and finishes bond without grit.
Mirka DEROS 6-inch Random Orbital Sander (with matching dust extraction setup) Fast, controlled surface prep for primer and paint; smooth trim holds coatings more evenly and looks sharper up close.
Graco Ultra Max II 695 Pro Airless Paint Sprayer Lays down a consistent film on long runs of fascia and corner boards; strong choice for high-end exterior paint systems.
A practical way to decide at the lumberyard
Start with your finish. If you will paint, prioritize stability and paint holding. Ask for clear vertical grain cedar or Accoya. Look for straight boards with tight grain and minimal knots. If you will stain, choose a species with natural durability and a look you love, then accept the maintenance schedule that comes with it.
Then look at the details of your house. If you have lots of built-up trim, pick a stable wood to keep joints tight. If your trim sits close to grade, lean toward higher decay resistance and be obsessive about keeping water away.
Exterior trim is not just decoration. It is a thin shield at the edge of the building. Choose a wood that acts like a shield, not like a sponge, and your paint and your patience will last a lot longer.